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Diffstat (limited to 'gcc/ada/scn-nlit.adb')
| -rw-r--r-- | gcc/ada/scn-nlit.adb | 371 |
1 files changed, 371 insertions, 0 deletions
diff --git a/gcc/ada/scn-nlit.adb b/gcc/ada/scn-nlit.adb new file mode 100644 index 00000000000..f027ba25b3a --- /dev/null +++ b/gcc/ada/scn-nlit.adb @@ -0,0 +1,371 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S C N . N L I T -- +-- -- +-- B o d y -- +-- -- +-- $Revision: 1.32 $ -- +-- -- +-- Copyright (C) 1992,1993,1994,1995,1996 Free Software Foundation, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 2, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- +-- for more details. You should have received a copy of the GNU General -- +-- Public License distributed with GNAT; see file COPYING. If not, write -- +-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- +-- MA 02111-1307, USA. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). -- +-- -- +------------------------------------------------------------------------------ + +with Uintp; use Uintp; +with Urealp; use Urealp; + +separate (Scn) +procedure Nlit is + + C : Character; + -- Current source program character + + Base_Char : Character; + -- Either # or : (character at start of based number) + + Base : Int; + -- Value of base + + UI_Base : Uint; + -- Value of base in Uint format + + UI_Int_Value : Uint; + -- Value of integer scanned by Scan_Integer in Uint format + + UI_Num_Value : Uint; + -- Value of integer in numeric value being scanned + + Scale : Int; + -- Scale value for real literal + + UI_Scale : Uint; + -- Scale in Uint format + + Exponent_Is_Negative : Boolean; + -- Set true for negative exponent + + Extended_Digit_Value : Int; + -- Extended digit value + + Point_Scanned : Boolean; + -- Flag for decimal point scanned in numeric literal + + ----------------------- + -- Local Subprograms -- + ----------------------- + + procedure Error_Digit_Expected; + -- Signal error of bad digit, Scan_Ptr points to the location at which + -- the digit was expected on input, and is unchanged on return. + + procedure Scan_Integer; + -- Procedure to scan integer literal. On entry, Scan_Ptr points to a + -- digit, on exit Scan_Ptr points past the last character of the integer. + -- For each digit encountered, UI_Int_Value is multiplied by 10, and the + -- value of the digit added to the result. In addition, the value in + -- Scale is decremented by one for each actual digit scanned. + + -------------------------- + -- Error_Digit_Expected -- + -------------------------- + + procedure Error_Digit_Expected is + begin + Error_Msg_S ("digit expected"); + end Error_Digit_Expected; + + ------------------- + -- Scan_Integer -- + ------------------- + + procedure Scan_Integer is + C : Character; + -- Next character scanned + + begin + C := Source (Scan_Ptr); + + -- Loop through digits (allowing underlines) + + loop + Accumulate_Checksum (C); + UI_Int_Value := + UI_Int_Value * 10 + (Character'Pos (C) - Character'Pos ('0')); + Scan_Ptr := Scan_Ptr + 1; + Scale := Scale - 1; + C := Source (Scan_Ptr); + + if C = '_' then + Accumulate_Checksum ('_'); + + loop + Scan_Ptr := Scan_Ptr + 1; + C := Source (Scan_Ptr); + exit when C /= '_'; + Error_No_Double_Underline; + end loop; + + if C not in '0' .. '9' then + Error_Digit_Expected; + exit; + end if; + + else + exit when C not in '0' .. '9'; + end if; + end loop; + + end Scan_Integer; + +---------------------------------- +-- Start of Processing for Nlit -- +---------------------------------- + +begin + Base := 10; + UI_Base := Uint_10; + UI_Int_Value := Uint_0; + Scale := 0; + Scan_Integer; + Scale := 0; + Point_Scanned := False; + UI_Num_Value := UI_Int_Value; + + -- Various possibilities now for continuing the literal are + -- period, E/e (for exponent), or :/# (for based literal). + + Scale := 0; + C := Source (Scan_Ptr); + + if C = '.' then + + -- Scan out point, but do not scan past .. which is a range sequence, + -- and must not be eaten up scanning a numeric literal. + + while C = '.' and then Source (Scan_Ptr + 1) /= '.' loop + Accumulate_Checksum ('.'); + + if Point_Scanned then + Error_Msg_S ("duplicate point ignored"); + end if; + + Point_Scanned := True; + Scan_Ptr := Scan_Ptr + 1; + C := Source (Scan_Ptr); + + if C not in '0' .. '9' then + Error_Msg ("real literal cannot end with point", Scan_Ptr - 1); + else + Scan_Integer; + UI_Num_Value := UI_Int_Value; + end if; + end loop; + + -- Based literal case. The base is the value we already scanned. + -- In the case of colon, we insist that the following character + -- is indeed an extended digit or a period. This catches a number + -- of common errors, as well as catching the well known tricky + -- bug otherwise arising from "x : integer range 1 .. 10:= 6;" + + elsif C = '#' + or else (C = ':' and then + (Source (Scan_Ptr + 1) = '.' + or else + Source (Scan_Ptr + 1) in '0' .. '9' + or else + Source (Scan_Ptr + 1) in 'A' .. 'Z' + or else + Source (Scan_Ptr + 1) in 'a' .. 'z')) + then + Accumulate_Checksum (C); + Base_Char := C; + UI_Base := UI_Int_Value; + + if UI_Base < 2 or else UI_Base > 16 then + Error_Msg_SC ("base not 2-16"); + UI_Base := Uint_16; + end if; + + Base := UI_To_Int (UI_Base); + Scan_Ptr := Scan_Ptr + 1; + + -- Scan out extended integer [. integer] + + C := Source (Scan_Ptr); + UI_Int_Value := Uint_0; + Scale := 0; + + loop + if C in '0' .. '9' then + Accumulate_Checksum (C); + Extended_Digit_Value := + Int'(Character'Pos (C)) - Int'(Character'Pos ('0')); + + elsif C in 'A' .. 'F' then + Accumulate_Checksum (Character'Val (Character'Pos (C) + 32)); + Extended_Digit_Value := + Int'(Character'Pos (C)) - Int'(Character'Pos ('A')) + 10; + + elsif C in 'a' .. 'f' then + Accumulate_Checksum (C); + Extended_Digit_Value := + Int'(Character'Pos (C)) - Int'(Character'Pos ('a')) + 10; + + else + Error_Msg_S ("extended digit expected"); + exit; + end if; + + if Extended_Digit_Value >= Base then + Error_Msg_S ("digit >= base"); + end if; + + UI_Int_Value := UI_Int_Value * UI_Base + Extended_Digit_Value; + Scale := Scale - 1; + Scan_Ptr := Scan_Ptr + 1; + C := Source (Scan_Ptr); + + if C = '_' then + loop + Accumulate_Checksum ('_'); + Scan_Ptr := Scan_Ptr + 1; + C := Source (Scan_Ptr); + exit when C /= '_'; + Error_No_Double_Underline; + end loop; + + elsif C = '.' then + Accumulate_Checksum ('.'); + + if Point_Scanned then + Error_Msg_S ("duplicate point ignored"); + end if; + + Scan_Ptr := Scan_Ptr + 1; + C := Source (Scan_Ptr); + Point_Scanned := True; + Scale := 0; + + elsif C = Base_Char then + Accumulate_Checksum (C); + Scan_Ptr := Scan_Ptr + 1; + exit; + + elsif C = '#' or else C = ':' then + Error_Msg_S ("based number delimiters must match"); + Scan_Ptr := Scan_Ptr + 1; + exit; + + elsif not Identifier_Char (C) then + if Base_Char = '#' then + Error_Msg_S ("missing '#"); + else + Error_Msg_S ("missing ':"); + end if; + + exit; + end if; + + end loop; + + UI_Num_Value := UI_Int_Value; + end if; + + -- Scan out exponent + + if not Point_Scanned then + Scale := 0; + UI_Scale := Uint_0; + else + UI_Scale := UI_From_Int (Scale); + end if; + + if Source (Scan_Ptr) = 'e' or else Source (Scan_Ptr) = 'E' then + Accumulate_Checksum ('e'); + Scan_Ptr := Scan_Ptr + 1; + Exponent_Is_Negative := False; + + if Source (Scan_Ptr) = '+' then + Accumulate_Checksum ('+'); + Scan_Ptr := Scan_Ptr + 1; + + elsif Source (Scan_Ptr) = '-' then + Accumulate_Checksum ('-'); + + if not Point_Scanned then + Error_Msg_S ("negative exponent not allowed for integer literal"); + else + Exponent_Is_Negative := True; + end if; + + Scan_Ptr := Scan_Ptr + 1; + end if; + + UI_Int_Value := Uint_0; + + if Source (Scan_Ptr) in '0' .. '9' then + Scan_Integer; + else + Error_Digit_Expected; + end if; + + if Exponent_Is_Negative then + UI_Scale := UI_Scale - UI_Int_Value; + else + UI_Scale := UI_Scale + UI_Int_Value; + end if; + end if; + + -- Case of real literal to be returned + + if Point_Scanned then + Token := Tok_Real_Literal; + Token_Node := New_Node (N_Real_Literal, Token_Ptr); + Set_Realval (Token_Node, + UR_From_Components ( + Num => UI_Num_Value, + Den => -UI_Scale, + Rbase => Base)); + + -- Case of integer literal to be returned + + else + Token := Tok_Integer_Literal; + Token_Node := New_Node (N_Integer_Literal, Token_Ptr); + + if UI_Scale = 0 then + Set_Intval (Token_Node, UI_Num_Value); + + -- Avoid doing possibly expensive calculations in cases like + -- parsing 163E800_000# when semantics will not be done anyway. + -- This is especially useful when parsing garbled input. + + elsif Operating_Mode /= Check_Syntax + and then (Errors_Detected = 0 or else Try_Semantics) + then + Set_Intval (Token_Node, UI_Num_Value * UI_Base ** UI_Scale); + + else + Set_Intval (Token_Node, No_Uint); + end if; + + end if; + + return; + +end Nlit; |